Initial Commit

openssl-1.0.2f/doc/crypto/mdc2.pod

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+=pod
+
+=head1 NAME
+
+MDC2, MDC2_Init, MDC2_Update, MDC2_Final - MDC2 hash function
+
+=head1 SYNOPSIS
+
+ #include <openssl/mdc2.h>
+
+ unsigned char *MDC2(const unsigned char *d, unsigned long n,
+                  unsigned char *md);
+
+ int MDC2_Init(MDC2_CTX *c);
+ int MDC2_Update(MDC2_CTX *c, const unsigned char *data,
+                  unsigned long len);
+ int MDC2_Final(unsigned char *md, MDC2_CTX *c);
+
+=head1 DESCRIPTION
+
+MDC2 is a method to construct hash functions with 128 bit output from
+block ciphers.  These functions are an implementation of MDC2 with
+DES.
+
+MDC2() computes the MDC2 message digest of the B<n>
+bytes at B<d> and places it in B<md> (which must have space for
+MDC2_DIGEST_LENGTH == 16 bytes of output). If B<md> is NULL, the digest
+is placed in a static array.
+
+The following functions may be used if the message is not completely
+stored in memory:
+
+MDC2_Init() initializes a B<MDC2_CTX> structure.
+
+MDC2_Update() can be called repeatedly with chunks of the message to
+be hashed (B<len> bytes at B<data>).
+
+MDC2_Final() places the message digest in B<md>, which must have space
+for MDC2_DIGEST_LENGTH == 16 bytes of output, and erases the B<MDC2_CTX>.
+
+Applications should use the higher level functions
+L<EVP_DigestInit(3)|EVP_DigestInit(3)> etc. instead of calling the
+hash functions directly.
+
+=head1 RETURN VALUES
+
+MDC2() returns a pointer to the hash value. 
+
+MDC2_Init(), MDC2_Update() and MDC2_Final() return 1 for success, 0 otherwise.
+
+=head1 CONFORMING TO
+
+ISO/IEC 10118-2, with DES
+
+=head1 SEE ALSO
+
+L<sha(3)|sha(3)>, L<EVP_DigestInit(3)|EVP_DigestInit(3)>
+
+=head1 HISTORY
+
+MDC2(), MDC2_Init(), MDC2_Update() and MDC2_Final() are available since
+SSLeay 0.8.
+
+=cut